Just bought a used 2000 model 400EX. Its making a light tapping noise that sounds like a valve adjustment, maybe. BUT, if you listen carefully, it also has a slight knock. Is this ususal for the EX? ........Until I bought this one I had never heard one run or rode one. I am just wondering if these sounds are usual after a few months of riding? The title says it was bought new in Jan. 2000, so its only 7 months old.

 

What did you pay for it? I am looking at a used one also...Did you have any taxes and registration to pay?

 

yes this is normal. whoever had it before you evidentlly didn't have the valves adjusted. get them adjusted as soon as possible to prevent engine damage.

 

even after i had my valves professionally done, they has a slight tapping... the valves very very lightly tap off of the valve covers.. you can see this by looking at one of the valve covers... i know 6 other 400ex's that do the same thing, i am sure it is normal

 

Yes , a very light knocking is normal and will be amplified with a skid plate. However if it becomes a loud knock you should have it checked out.

 

A way to get rid of the skid plate rattle is to use double sided foam tape for the contact points...

 

I practicly stole the 400, I paid only $3300 for it.......... And for some reason I have also noticed the cycle trader having MANY 400EX's for sale and at cheaper prices, I wonder why?

 

I didn't say my skid plate rattled I said that the engine noise would be amplified by a skid plate.(Because of an echo effect)
You are correct on the skid plate though.